Effect of different extraction methods on micro-component composition and oxidative stability of oil produced from African pear (<i>Dacryodes edulis</i>) mesocarp Oil

Abstract

Three different methods, including Soxhlet, traditional and screw press, were used to extract oil from African pear pulp. The oils were analysed for selected minerals and phytonutrients; stored for 4 weeks and analysed for oxidative changes. The microcomponents results ranged from 0.00 to 41.50% for chlorophyll, 0.00 to 1.25 µg/100g for total carotenoids, 0.02 to 0.04 mg/100g for iron, 0.00 to 0.01 mg/100g for copper, and 18.25 to 208.50 mg/100g for vitamin E. The oxidative stability results showed that peroxide values ranged from 0.13 to 2.69 meq O2/kg in week 1 to 0.92 to 3.62 meq O2/kg in week 4; FFA ranged from 0.36 to 7.04% in week 1 to 0.39 to 11.47% in week 4; density ranged from 0.89 to 0.91 g/cm3 in week 1 to 0.91 to 0.98 g/cm3 in week 4; viscosity ranged from 17.17 to 51.57 RVU in week 1 to 20.31 to 55.05 RVU in week 4 and thiobarbituric acid level ranged from 0.02 to 1.11 mg/g in week 1 to 0.09 to 1.31 mg/g in week 4. Soxhlet extraction method produced oil of best quality with significantly (p < 0.05) higher mineral and phytonutrient contents, and of a longer storage stability.